Rack advice please

[Balrog]

I've just seen they sell a straight pull up bar for the thor cage for 30 pounds.

[AndyEp]

Have you looked at Mirafit. I’ve been very happy with mine and on a budget seem great value. Allows more money for the bar

[skinnybones]

I've just seen they sell a straight pull up bar for the thor cage for 30 pounds.

Yeah, thats quite new. Been considering getting one myself as I've had to put my chin up bar on upside down to allow my head not to smack the ceiling, which on the garage cage brings it to 'head knocking' level so Ive got to be wary when stepping back. The straight bar would clear my head standing, yet still allow clearance to the ceiling on chins. Tell you what, thinking about it now Im ordering it.

[Utred]

Hi, I'm also located in the UK and would like to fabricate the SS rack. Could anybody please provide a metric version of the CAD drawing? I took the drawing to a local steel works and they are happy to quote but have stipulated that all dimensions must be metric.

[stef]

Could anybody please provide a metric version of the CAD drawing?

Are you serious? Put in a couple minutes and do the work yourself. Even if you're horrific at math, surely you can use an online calculator and a pen to get this done.

[Mark Rippetoe]

This rack cannot be manufactured in metric units. It was designed in English units, and it will not be either square or plumb in metric units. Do not attempt this, I'm warning you!

[Utred]

Are you serious?

Erm yes, that's why I asked?
As you highlight, imperial to meric conversions can be done easily enough.
The difficulty begins when the specified imperial steel C sections aren't standard stock in metric dimensions.
No doubt you'll say, get the size up? Ok. We'll work it from that assumption. The 'J cup' bolt specification of 1-1/8 7x6 does not have an exact metric equivalent in manufacture, it is an imperial specification construction bolt that can't be purchased in the UK. Again, for arguments sake let's get the bolt closest dimensionally but again larger. What size to drill the hole? No doubt again, easy you'll say, get a 'Zeus' book.
Ok. I've got the hole size from there, but the annular cutter does not come in that size. So again you get the closest but larger, now the tolerance specification of the original imperial CAD drawing has been exceeded. You've removed extra material at every hole drilled, the holes are larger therefore closer to the edge of the C sections, have you compromised intended safe working load, structural integrity for something that you are hoping saves you when the worst happens and you fail with 600lbs inside the rack?
Now the uprights have been oversize drilled what size of safety/racking bars should I spec?
See where all of this is going?
It is a naive and fanciful idea to assume that it is as simplistic as to just covert numbers that would result in the exact same specification product being made.
Obviously it can be bespoke made to these dimensions, but the material would be a helluva lot more expensive due to not using standard stock sizes, it then becomes a lot more expensive overall and therefore less attractive.
I just wanted a metric CAD drawing that someone has considered all of these problems and manufactured a safe final product at a reasonable cost due to using stock metric sizing. I'm sure it has been done many times?
Handing a engineering drawing over to a manufacturer with directly converted dimensions would result in a very very expensive rack being made.

[Mark Rippetoe]

These are insurmountable difficulties. This is why this rack has never been manufactured in Europe before. Don't try it.

[Utred]

The difficulties are not insurmountable. Enjoying a problem, I specced the imperial CAD drawing with the nearest metric equivalent, adhering to tolerances by getting round stock turned down and priced up the raw material required. This is where the problem lies. It was only slightly less than the cost of a delivered Rogue R3 bolt together. I'm not sure if the price of steel is being pushed up due to Covid though. Also by altering the rig dimensionally it is no longer the SS product. It would be a lot beefier and to keep the internal dimensions the same, the external footprint also increases which again makes it less attractive. Kinda annoying though that such a simple structure is cheaper to purchase than make yourself. Guess that's commerce for you. Anyways, thanks for the input and it is good that the imperial drawings are out there for people to use.